Chosen Solution
Hello, I replaced the hard drive on a Acer Aspire V5-571 due to the old one crashed and couldn’t boot anymore. It was a windows 8 but i installed a hard drive that has windows 7 installed on it. Now when i’m trying to boot, i just get the message “operating system not found”. I can’t seem to get it into bios or anything. Hernando
@johnskinner , Just wondering if a power refresh would reset the BIOS back to default values? You can only try. Disconnect charger if connected. Disconnect main battery Remove or disconnect cmos battery (you don’t state the model number but this may help) If it is a coin cell battery, rather than a battery with a cable connection, remember the orientation of the battery for when you need to reinstall it, usually it is +ve on top. Press and hold the laptop power button for 20 seconds then release. Re-install (reconnect) the cmos battery, Reconnect the main battery. Connect and switch on the charger and then turn on the laptop and attempt to enter BIOS by pressing F2.
